Fracturing of subterranean formations involves positioning a downhole tool in a borehole adjacent a formation, sealing an interval of the borehole along the tool and adjacent the formation, increasing a fluid pressure in the sealed interval, and monitoring the fluid pressure. The pressure levels to initiate and propagate a fracture can be used determine geomechanical characteristics of the formation such as described in U.S. Pat. Nos. 5,165,274, 5,353,637, 6,076,046, or 6,705,398, all of which are incorporated herein by reference in their entireties. The geomechanical characteristics of the formation may then be utilized to design drilling and/or hydrocarbon production operations. Further, formation sampling operations and, more generally, fluid production from or injection into a formation may be facilitated by fracturing the formation within the sealed interval prior to extracting or injecting fluids.